Calcium Carbonate 250 mg or 500 mg: This is used for the treatment or prevention of calcium depletion in patients in whom dietary measures are inadequate. Conditions that may be associated with calcium deficiency include hypoparathyroidism, achlorhydria, chronic diarrhea, vitamin D deficiency, steatorrhea, sprue, pregnancy and lactation, menopause, pancreatitis, renal failure, alkalosis, and hyperphosphataemia. Calcium Carbonate is being used increasingly often to treat hyperphosphataemia in chronic renal failure as well as those on continuous ambulatory peritoneal dialysis (CAPD) and haemodialysis.
Many patients are unable to tolerate sufficient doses for complete phosphate control and require additional measures such as stringent dietary phosphate restriction or relatively small doses of aluminium hydroxide. Calcium Carbonate containing preparations can provide short-term relief of dyspeptic systems but are no longer recommended for long-term treatment of peptic ulceration.
Calcium Carbonate 1000 mg: This is indicated for the management of conditions associated with hyperidity and for fast relief of acid indigestion, heartburn, sour stomach and upset stomach.
Calcium carbonate reacts with gastric acid to produce a salt and water. For calcium carbonate the postulated chemical reaction is:
CaCO3 + 2HCl = CaCl2 + H2O + CO2
Two grams of calcium carbonate will readily bring 100 ml of hydrochloric acid to a pH above 6. The increase in gastric pH diminishes the activity of pepsin in the gastric secretion. Up to 30% of the oral calcium load may be absorbed.